I hate "C"

[Mike Betts]

Originally Posted by maniac_2040

...Why does it throw off the stack variables by two bytes each?(Not that I know much about the "stack" anyways ) and how did you know this?

I've been working with embedded processors for over 25 years (and vacuum tubes, et cetera for 10 years before that). I think that I first learned about C and stack variables in college (circa 1978).

dcbrown's explanation is correct. When viewed from a pure "software" perspective, the fact that this processor passes parameters on the stack is, perhaps, confusing. C allows a variable argument list and it is up to the called function (in this case, printf) to parse the format string (the first parameter of the function is actually a pointer to a string) and determine how many variables there are and how large each one is. Your first %d in your format string indicated a 2 byte variable was the second parameter on the stack. When you put a long variable in the calling statement, 4 bytes were pushed onto the stack. That meant that all of your subsequent parameters were 2 bytes off...

I would refer you to K&R for more details. It was the bible back in the 70's and, in my opinion, it is still the bible.

For specifics on C as implemented for this processor, I'd look here.

Regards,

Mike